Shield With Heat Exchanger For Sputtering Chamber
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Solution Overview
Problem
In substrate processing chambers, especially PVD chambers, the accumulation of sputtered deposits on internal components leads to increased downtime for cleaning, substrate damage, and thermal stress due to excessive heating of shields and liners, which reduces operational efficiency and increases costs.
Innovation Solution
A process kit comprising a shield with a heat exchanger and specifically designed rings that reduce deposition on internal chamber surfaces, prevent substrate sticking, and manage thermal stress through a single-piece shield and anti-lift bracket, allowing for increased operational time and reduced maintenance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If process kit components are used to protect chamber sidewalls from sputtered deposits, then the accumulation of deposits on internal chamber surfaces is reduced, but the components themselves accumulate deposits that require periodic cleaning and cause chamber downtime
Solution Approach 1:
The process kit components (shields, liners, rings) serve as intermediary elements that intercept sputtered deposits before they reach the chamber sidewalls. These components are strategically positioned to absorb the harmful deposition flux, protecting the permanent chamber structure while concentrating the accumulation on removable, easily cleanable parts.
Solution Approach 2:
The process kit components are designed to be periodically removed, cleaned, and reinstalled. This allows the accumulated deposits to be discarded from the system by removing and cleaning the shields and liners, restoring them to a clean state for continued use without requiring chamber disassembly or permanent structural modification.
2Reliability
If shields and liners are exposed to sputtering plasma, then they protect internal chamber structures from erosion, but the shields and liners heat up excessively causing thermal stress and potential damage
Solution Approach 1:
The shields and liners act as intermediary protective barriers between the sputtering plasma and the permanent chamber structures. They absorb the erosive plasma flux and the associated thermal load, protecting the underlying chamber components while concentrating the thermal stress on the removable shields and liners themselves.
Solution Approach 2:
The shields and liners are designed to be periodically removed and replaced. This allows them to absorb thermal stress and potential damage during operation, then be restored or replaced during maintenance periods, ensuring continuous protection without compromising the permanent chamber structure.
3Loss of substance
If deposition rings are positioned close to the substrate periphery to reduce sputtered deposit accumulation, then less material accumulates on internal surfaces, but the substrate may stick to the rings causing substrate damage during removal
Solution Approach 1:
The deposition rings are designed with specific local geometric features including gaps, varying thicknesses, and strategic positioning that create zones of reduced deposition. These local variations in ring structure control where material accumulates, preventing excessive buildup in areas that would cause substrate sticking while still protecting other internal surfaces.
Solution Approach 2:
The deposition rings are segmented with gaps and discontinuities rather than being continuous structures. This segmentation allows the substrate to be partially supported while reducing the surface area available for deposit accumulation that would cause sticking, and enables easier substrate removal by creating release zones.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution significantly reduces sputtered deposits on internal chamber components, minimizes substrate damage, and maintains thermal stability, thereby increasing the number of substrates that can be processed without shutdown and enhancing overall chamber uptime by at least 85%.
Implementation Method 1
A heat exchanger can be used for cooling the shield
Implementation Method 2
the target is typically electrically biased, and the substrate maintained at an electrical floating potential, to generate a plasma in the chamber which causes sputtering of the target
Implementation Method 3
generate a plasma in the chamber which causes sputtering of the target
Data Source
AI summary
A shield encircles a sputtering target that faces a substrate support in a substrate processing chamber. The shield comprises an outer band having a diameter sized to encircle the sputtering target, the outer band having upper and bottom ends, and the upper end having a tapered surface extending radially outwardly and adjacent to the sputtering target. A base plate extends radially inward from the bottom end of the outer band. An inner band joined to the base plate at least partially surrounds a peripheral edge of a substrate support. The shield can also have a heat exchanger comprising a conduit with an inlet and outlet to flow heat exchange fluid therethrough.